The present invention is concerned with the mechanism for manipulating transversely elongated longitudinal clamping rails in automatic carton closing machines for adjusting the intervening space therebetween to convert them to suitably spaced lateral side guide rails extending longitudinally through the machine to define a path of forward travel of a plurality of successive cartons. It is particularly concerned with the satisfaction of a desire to space them transversely with a tolerance which will permit free advance, without damage, of all of a group of set-up cartons, which may be loaded for shipping contents, and intended to be of about the same size while accommodating small degrees of variances in widths thereof and to accomplish this by relatively simple equipment that is easily added to conventional equipment for manipulating the side guide rails of automatic carton closing machines of the types disclosed in U.S. Pats. No. Re. 26,440 of Aug. 13, 1968 (and its parent U.S. Pat. No. 3,236,022); U.S. Pat. No. 3,382,645 of May 14, 1968; and U.S. Pat. No. 3,496,697 of Feb. 24, 1970. Disclosures of those patents which are pertinent to the present invention are embodied herein by reference. In order to accomplish this end automatic control mechanism will be set to cause widely spread side guide rails to respond to a dictated command to move transversely inward toward opposite sides of an entering first loaded carton of such a group of intended same size and then to be separated transversely back through the desired relatively small additional space of tolerance. Following the teaching of the present invention a variety of types of means may occur to one which might be substituted for a preferred means to adjust the width of the transverse space between the opposed longitudinal side guide rails when first set to process successively therebetween a series of assumed similar width loaded cartons of a group intended to be of the same size and then provide a moderate tolerance between these guide rails that will avoid damaging or jamming of any of these cartons, that may be slightly wider due to overfilling or other cause, as these cartons are moved successively forward therebetween.
The first carton of the group of similar size to be advanced through the machine may serve as a gauge for the primary adjustment of the spacing between these side guide rails and then various types of differing devices may serve to assure the attainment of the small amount of the desired supplementary spacing tolerance. For example, the mechanisms which move these guide rails inward and outward relative to each other may be connected to the latter by resilient means which provides the desired tolerance. A longitudinally extending facing shoe may be mounted to the face of one of these guide rails, or both may be so equipped, and resilient means between the rail face and such facing shoe may provide the requisite tolerance, particularly if the entrance ends of these facing shoes are flared outwardly to define a feeding tapered space therebetween. Also, the guide rails moving mechanism may impose the transverse movement thereto through camming devices wherein relatively high lobe means dictate initial or primary relative rail spacing and then relatively low cam lobe means attain the secondary or additional tolerance spacing. However, the preferred mechanism for such a spacing tolerance service is that which is detailed herein as pertaining to a latching device associated with the side guide rails transverse driving mechanism, with this latching device being biased by alterable or change means to effect the needed repositioning of the latch or the change in the holding action.
It is thus an object of the present invention to attain such relatively minor tolerance spacing of the side guide rails by embodying in their transverse moving equipment means that moves in proportion to the degree of motion of such equipment for attaining the basic spacing of the side guide rails for such a size of loaded cartons, and means which then further spaces them apart the desired relatively small additive tolerance distance.
More specifically, it is an object of the present invention to embody in the side guide rails transverse moving equipment a toothed rack or pinion means which moves in proportion to the degree of motion of this equipment, and associate therewith a floatably mounted means to engage such rack or pinion so that the motion freedom that this latter means has determines and allows the relatively minor amount of tolerance adjustment desired.
A preferred form of the equipment to effect the basic spacing of the side guide rails includes a double-ended pneumatic motive cylinder having its piston connected by flexible pull tether means, e.g., cable or linked chain, to the side guide rails. Valving of pressurized gaseous medium, such as air, in the supply ducts connected to the cylinder permits the latter and its piston to act as an elastic cushioning means, so that additional driving force applied to such tether means may translate the latter a limited additional amount, to provide the desired additional spacing tolerance. Such additional driving force may be applied by suitable rack or gear means that moves with the tether means and is engageable by latch means to apply therethrough the desired additional translation of this tether means. Desirably gear means may be rotated by longitudinal translation of the tether means, and vice versa, so that after the primary rail spacing is attained by drive of the tether means from the double-ended cylinder, the secondary tolerance spacing may be added by rotating the gear means through a radial angle by engaging it with the latch means as a driver and swinging the latter.
In accordance with the present invention it has been found that a practical and preferred means for effecting such swing of the gear means driver may be in the form of a pair of single-ended pneumatic motive cylinders with the front end of one pivoted on the axis of the gear means and its projecting piston rod carrying the latch means to engage this gear means for the relatively small angular drive of the latter. In turn, the latch means is swung by arcuate swing of this motive cylinder and, for this purpose, the back end of the latter may be pivotally connected to the projecting piston of the other of this pair of single-ended cylinders with the latter having its back end pivotally mounted to a fixed position support.